Contrary to the ads that you may see on television, juices are not more healthful than fruits or vegetables. How can an extract from food be more healthful than that food?

For most people, they are much less healthful. For example, a glass of orange juice contains about one tenth as much fiber as an orange and twice the calories. Diabetics shouldn't drink fruit juices because they drive blood sugar levels too high, nor should people who are trying to lose weight drink fruit juices because a rise in sugar calls out extra insulin that makes you hungry.

The CARDIA study shows that all sugared drinks, including fruit juices, raise total cholesterol, the bad LDL cholesterol, triglycerides, and blood pressure (American Journal of Clinical Nutrition, August 13, 2010). People who drink fruit juice also have much larger waist circumferences. Abdominal obesity means that a person has high insulin levels and is at markedly increased risk for heart attacks and diabetes.

Taking sugar in drinks when you are not exercising increases risk for heart attacks, diabetes and premature death. Before food can pass from the stomach into the intestines, it must be converted to a liquid soup. No solid food passes into the intestines. When solid food enters your stomach, the pyloric sphincter at the end of the stomach closes and the stomach continuously squeezes the food until it is turned into a liquid soup. This can take up to four hours which markedly delays the rise in blood sugar. Since fruit juice is already a liquid, it passes immediately into the bloodstream to cause a high rise in blood sugar.

Here's how high rises in blood sugar cause heart disease: When blood sugar levels rise too high:
• your pancreas releases huge amounts of insulin which
• converts sugar to triglycerides (high triglycerides), which clog up your bloodstream to increase risk for clots, so
• you use up huge amounts of your good HDL cholesterol (low HDL cholesterol) in carrying triglycerides and your bad LDL cholesterol from your bloodstream into your liver.
• Low HDL (good) cholesterol causes heart attacks because HDL is not available to carry cholesterol and triglycerides from your bloodstream.
• High insulin levels constrict arteries to cause heart attacks.
• High blood sugar levels cause sugar to stick to the surface membranes of cells to destroy them and cause all the horrible side effects of diabetes.
• High triglycerides in your liver cause a fatty liver that can lead to diabetes.

Don't be fooled by juices that claim that they supply 100 percent of your daily needs for vitamin C and A. Most drinks that can make that claim have artificial vitamins added to the drink and are no better for you than juices that have only 10 percent of your daily requirements. Adding calcium to fruit juices is reasonable because there are no known harmful effects and some people do not get enough calcium from other foods that they eat.

Manufacturers use terms that are deceptive. "Made from real fruit" is nonsensical. If the juice in not made from real fruit, it is not juice. The term "all natural" is absurd.

There are no known advantages or disadvantages to drinking fruit juice that has first had water removed to form a concentrate and then had the water added back in to form the juice. This process does not destroy nutrients and is not harmful.

It really doesn't make much difference whether you drink juice that is 100 percent fruit juice or made from 50 percent sugar water and 50 percent juice. Some fruits have higher water and sugar content; others must have water or sugar or both added to make them palatable. All juices contain around 8 to 10 percent sugar because that's the concentration of sugar that tastes best and that most people prefer. "All fruit" juices often use added sugars extracted from grapes, apples or other fruits rather than from sugar cane. There is no difference between any type of sugar added to a diluted fruit juice and the sugar that was originally in the fruit. Both are lower in fiber than the fruit, so they both cheat you of fiber, and since they both contain the same amount of sugar, they affect diabetics and overweight people in the same bad way by driving their blood sugars higher.

Pasteurized means that the fruit juice was heated to kill germs. You are less likely to be infected with E coli from a pasteurized drink and pasteurization does not reduce the amount of nutrients in a drink. Ultraviolet light, freezing, dehydrating and bubbling ozone through a drink get rid of germs and do not reduce nutrients.

The bottom line is to eat whole fruits and vegetables, and drink juices only if you can afford the extra calories and sugar. You gain nothing extra from juicing, and diabetics and overweight people should restrict their intake of juices because they have the same effect as any sugared beverages.

About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities.
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